The terminologies are used in this invention as following:
Gesture: The finger touch actions on screen, like single point touch, touch slice, 2 points pinch (this is the one used in this invention), multi touches spin;
API: Application Programming Interface;
iOS: iOS is the operation system of Apple, run on Apple's mobile devices like iPhone, iPad;
The traditional ECG measurement is that doctors use the dividers to lock 2 points on ECG (on paper), and move the dividers on the standard ECG ruler to read the intervals between two points;
Alternativly,the ECG ruler (or other similar tool)is used to measure ECG directly on the display screens.
Disadvanges of the Traditional Methods:                {circle around (1)} Obviously it is not to target the ECG which is displyed on screens;        {circle around (2)} The operations are relatively complicated;        {circle around (3)} When measuring vertial interval, an additional ruler is needed to get the 2 points exactly on the same x coordinate.        
On non-touch screen devices like PC screen, the measurement of ECG with PC mouse is utilized in the prior art which clicks on the initial point, drags mouse to the next point, then calculates.
The patent application (CN 200710092530.3) tiltled as “Approach of ECG measurement” discloses an ECG measurement approach which displays ECG waves on the screens, then determines the unit convert factor. After numberious of clickings on the wave top point, wave beginning and wave ending points with PC mouse, all clicked point coordinates are saved and calculated. The present invention discloses a method to use touch screen which replaces the clicks with PC mouse which does not use the screen touch feature for ECG measurement.
Neither the traditional measure approach using rulers, nor the mouse clicking and draging based approach, is user-friendly to yield accurate measurement for ECG.
In the prior art, there is no similar application on touch-screen devices as disclosed in the present invention, while the traditional mouse based approach can be not applied for the widely used touch screen devices in the field of ECG measurement. The present invention reveals a novel process of ECG measurement with a touch screen device.